I'm reading the source code of the Apache2.2 and I found that when I use the prefork module,it call the ap_process_connection to deal with a connection and in this method it calls the ap_run_pre_connection.
When it comes to here,I can find neither ap_run_pre_connection nor pre_connection (I find a macro named AP_DECLARE_HOOK, it linked the ap and _hook_ before the name pre_connection).
Where can I find the next step?
You can find the modules that participate in this hook by looking for ap_hook_pre_connection.
AP_IMPLEMENT_HOOK_RUN_ALL(int,pre_connection,(conn_rec *c, void *csd),(c, csd),OK,DECLINED)
AP_IMPLEMENT_HOOK_RUN_ALL means multiple modules that called ap_hook_pre_connection() will be run until an error is returned
/**
* Implement an Apache core hook that runs until one of the functions
* returns something other than ok or decline. That return value is
* then returned from the hook runner. If the hooks run to completion,
* then ok is returned. Note that if no hook runs it would probably be
* more correct to return decline, but this currently does not do
* so. The implementation is called ap_run_<i>name</i>.
The actual impl of ap_run_pre_connection is just a macro that loops through a linked list of registered functions. See apr_hooks.h
Related
Is there a way to make the logged user (on superset) to make the queries on impala?
I tried to enable the "Impersonate the logged on user" option on Databases but with no success because all the queries run on impala with superset user.
I'm trying to achieve the same! This will not completely answer this question since it does not still work but I want to share my research in order to maybe help another soul that is trying to use this instrument outside very basic use cases.
I went deep in the code and I found out that impersonation is not implemented for Impala. So you cannot achieve this from the UI. I found out this PR https://github.com/apache/superset/pull/4699 that for whatever reason was never merged into the codebase and tried to copy&paste code in my Superset version (1.1.0) but it didn't work. Adding some logs I can see that the configuration with the impersonation is updated, but then the actual Impala query is with the user I used to start the process.
As you can imagine, I am a complete noob at this. However I found out that the impersonation thing happens when you create a cursor and there is a constructor parameter in which you can pass the impersonation configuration.
I managed to correctly (at least to my understanding) implement impersonation for the SQL lab part.
In the sql_lab.py class you have to add in the execute_sql_statements method the following lines
with closing(engine.raw_connection()) as conn:
# closing the connection closes the cursor as well
cursor = conn.cursor(**database.cursor_kwargs)
where cursor_kwargs is defined in db_engine_specs/impala.py as the following
#classmethod
def get_configuration_for_impersonation(cls, uri, impersonate_user, username):
logger.info(
'Passing Impala execution_options.cursor_configuration for impersonation')
return {'execution_options': {
'cursor_configuration': {'impala.doas.user': username}}}
#classmethod
def get_cursor_configuration_for_impersonation(cls, uri, impersonate_user,
username):
logger.debug('Passing Impala cursor configuration for impersonation')
return {'configuration': {'impala.doas.user': username}}
Finally, in models/core.py you have to add the following bit in the get_sqla_engine def
params = extra.get("engine_params", {}) # that was already there just for you to find out the line
self.cursor_kwargs = self.db_engine_spec.get_cursor_configuration_for_impersonation(
str(url), self.impersonate_user, effective_username) # this is the line I added
...
params.update(self.get_encrypted_extra()) # already there
#new stuff
configuration = {}
configuration.update(
self.db_engine_spec.get_configuration_for_impersonation(
str(url),
self.impersonate_user,
effective_username))
if configuration:
params.update(configuration)
As you can see I just shamelessy pasted the code from the PR. However this kind of works only for the SQL lab as I already said. For the dashboards there is an entirely different way of querying Impala that I did not still find out.
This means that queries for the dashboards are handled in a different way and there isn't something like this
with closing(engine.raw_connection()) as conn:
# closing the connection closes the cursor as well
cursor = conn.cursor(**database.cursor_kwargs)
My gut (and debugging) feeling is that you need to first understand the sqlalchemy part and extend a new ImpalaEngine class that uses a custom cursor with the impersonation conf. Or something like that, however it is not simple (if we want to call this simple) as the sql_lab part. So, the trick is to find out where the query is executed and create a cursor with the impersonation configuration. Easy, isnt'it ?
I hope that this could shed some light to you and the others that have this issue. Let me know if you did find out another way to solve this issue, or if this comment was useful.
Update: something really useful
A colleague of mine succesfully implemented impersonation with impala without touching any superset related, but instead working directly with the impyla lib. A PR was open with the code to change. You can apply the patch directly in the impyla src used by superset. You have to edit both dbapi.py and hiveserver2.py.
As a reminder: we are still testing this and we do not know if it works with different accounts using the same superset instance.
Up to now I get only an error message if something inside my SAP RFC function is wrong
pyrfc._exception.ABAPRuntimeError: RFC_ABAP_MESSAGE (rc=4): key=No authorization,
message=No authorization [MSG: class=00, type=E, number=001, v1-4:=No authorization;;;]
It would increase the development speed a lot if I could get a stacktrace of ABAP function. Is there a way to get a stacktrace like for example in Python?
Related: https://softwarerecs.stackexchange.com/questions/52350/sentry-event-from-exception-to-html
Sentry uses a particular JSON to represent a stacktrace and the content of the local variables. Above link contains an example.
Stack trace inside ABAP can be called
with the class cl_abap_get_call_stack.
Local variables are not included in the stack trace returned by the class cl_abap_get_call_stack.
But you could use a log-point to monitor local variables and the stack trace. Log-points can be created, changed and viewed in transaction saab.
A example code snippet:
DATA(formatted_stack) =
cl_abap_get_call_stack=>format_call_stack_with_struct(
cl_abap_get_call_stack=>get_call_stack( ) ).
LOG-POINT ID my_log_point FIELDS formatted_stack
local_variable1 local_variable2.
For the authorization-error, please check transaction su53.
When you see the red authorization-object S_RFC, it means you are not allowed to call the function module in any way!
With ABAP 753 release there was introduced such structure as EPP - Extended Passport.
It seems to be doing something that you want, i.e. showing trace of the called system. I put "seems to be" because I have no 753+ system by my hands so I cannot check in practice.
From the description it should do what you want:
An Extended Passport (EPP) is a data structure that can be sent from a client to a server and is used to analyze call stacks
Extended Passport can be used by frameworks and analysis tools to track external call stacks in communication between clients and servers beyond system boundaries. The values of the EPP components can be saved to log files and used for monitoring. One example of this are short dumps, which all display the most important EPP components.
The DEMO_EPP gives the following usage pattern of EPP:
cl_demo_epp=>init( ).
"this program
cl_demo_epp=>append( ).
"Calling RFC to remote instance
CALL FUNCTION 'DEMO_RFM_EPP_1' DESTINATION instance.
"New SAP LUW
CALL FUNCTION 'DEMO_UPDATE_DELETE' IN UPDATE TASK
EXPORTING
values = VALUE demo_update_tab( ).
COMMIT WORK.
cl_demo_epp=>append( ).
cl_demo_output=>new(
)->begin_section( `Extended Passport (EPP)`
)->display( name = 'EPP Trace'
data = cl_demo_epp=>get( ) ).
I got many scripts. I want to be able to manage them all in 1 in script.
What I want is that the main script will activate a certain script, then when the secondary script is done, it returns a value to the main script. After that, the main script calls another secondary script, etc...
Is there a proper way to do this?
More precise question:
Is it possible to activate a AHK script from another script AHK?
At the moment, to detect that at a secondary script is complete, the way I currently use is that right before the end of the secondary script, I press a combinaison of keys that the main script will detect. And once detected, it will increase a main script variable by one and this will trigger the activation of the next script. Is there a better way to achieve this?
The main script could call the other scripts using RunWait. The scripts could then communicate back before terminating themselves.
The best option for communication would be to use OnMessage.
The following is a working example from the documentation:
; Example: Send a string of any length from one script to another. This is a working example.
; To use it, save and run both of the following scripts then press Win+Space to show an
; InputBox that will prompt you to type in a string.
; Save the following script as "Receiver.ahk" then launch it:
#SingleInstance
OnMessage(0x4a, "Receive_WM_COPYDATA") ; 0x4a is WM_COPYDATA
return
Receive_WM_COPYDATA(wParam, lParam)
{
StringAddress := NumGet(lParam + 2*A_PtrSize) ; Retrieves the CopyDataStruct's lpData member.
CopyOfData := StrGet(StringAddress) ; Copy the string out of the structure.
; Show it with ToolTip vs. MsgBox so we can return in a timely fashion:
ToolTip %A_ScriptName%`nReceived the following string:`n%CopyOfData%
return true ; Returning 1 (true) is the traditional way to acknowledge this message.
}
; Save the following script as "Sender.ahk" then launch it. After that, press the Win+Space hotkey.
TargetScriptTitle = Receiver.ahk ahk_class AutoHotkey
#space:: ; Win+Space hotkey. Press it to show an InputBox for entry of a message string.
InputBox, StringToSend, Send text via WM_COPYDATA, Enter some text to Send:
if ErrorLevel ; User pressed the Cancel button.
return
result := Send_WM_COPYDATA(StringToSend, TargetScriptTitle)
if result = FAIL
MsgBox SendMessage failed. Does the following WinTitle exist?:`n%TargetScriptTitle%
else if result = 0
MsgBox Message sent but the target window responded with 0, which may mean it ignored it.
return
Send_WM_COPYDATA(ByRef StringToSend, ByRef TargetScriptTitle) ; ByRef saves a little memory in this case.
; This function sends the specified string to the specified window and returns the reply.
; The reply is 1 if the target window processed the message, or 0 if it ignored it.
{
VarSetCapacity(CopyDataStruct, 3*A_PtrSize, 0) ; Set up the structure's memory area.
; First set the structure's cbData member to the size of the string, including its zero terminator:
SizeInBytes := (StrLen(StringToSend) + 1) * (A_IsUnicode ? 2 : 1)
NumPut(SizeInBytes, CopyDataStruct, A_PtrSize) ; OS requires that this be done.
NumPut(&StringToSend, CopyDataStruct, 2*A_PtrSize) ; Set lpData to point to the string itself.
Prev_DetectHiddenWindows := A_DetectHiddenWindows
Prev_TitleMatchMode := A_TitleMatchMode
DetectHiddenWindows On
SetTitleMatchMode 2
SendMessage, 0x4a, 0, &CopyDataStruct,, %TargetScriptTitle% ; 0x4a is WM_COPYDATA. Must use Send not Post.
DetectHiddenWindows %Prev_DetectHiddenWindows% ; Restore original setting for the caller.
SetTitleMatchMode %Prev_TitleMatchMode% ; Same.
return ErrorLevel ; Return SendMessage's reply back to our caller.
}
Well, I'm not sure why you'd want to make one script run another one... but here are a few other methods:
Include a script in another one
but, you know you can include a script inside another one, right? That is, you can use another scripts functions in your main script.
Make sure a particular script is loaded
"I got many scripts" too. Sometimes I need to make sure that a particular one is included before I can use it, so I put this at the top:
;make sure core.ahk is loaded since it is required
#include c:\ahk\core.ahk
And you don't have to worry about it getting included more than once (unless you need it) because:
#Include ensures that FileName is included only once, even if multiple inclusions are encountered for it. By contrast, #IncludeAgain allows
multiple inclusions of the same file, while being the same as #Include
in all other respects.
Now, when I include file.ahk in main.ahk, I am assured of no problems using the functions from core.ahk that file.ahk requires. And even if I include core.ahk again in main.ahk it is no worry (unless it contains subroutines instead of just functions - in which case they get run at the point where they were included, so it's best not to put subroutines in your ahk libraries).
Use good ole' RUN on Scripts
Aside from that, you know you can always use the run command to launch an ahk script. You don't have to do all that fancy WM_SENDMESSAGE stuff.
Communicate betweenst scripts using a hidden GUI
Another way for two scripts to communicate between each other is for script #1 to keep open a hidden GUI window that has an edit box and a submit button. This window will never be shown. Now, Script #2 hunts for that message box, uses send to put a string in the edit box, and then control-click to push the submit button. Now script #1 has just received input from script #2. And you don't even have to hunt for the window if you put the windows hwnd value in both scripts (so they already know it ahead of time). This works like a charm.
Tell if a script has completed
If you use ahk's run command, there is an parameter that will give you back the PID of that process (PID = Process ID). You can use this PID to check to see if the script is running, and you can use it to terminate the process.
Also, if you use runwait - the script using that command will pause and wait for the runn-ed process to complete and close before continuing.
theoretically you could also use a file object between the scripts as a sort of stdin/stdout method as when opening a file with the file object you can set it as shared.
You could also set an environment variable and pass the name of the variable to the script ,given that you have setup argument handling in the target script, which then sets the environment variable value on closing. using RunWait and this you could find out what the return result of the script is after it runs.
Lastly, look into using a function as that is probably the "best practice" for what you are trying to do. Since a function can do anything a script can do and you can pass it an array to operate on or with using ByRef on the array param. This would mean that you don't have to write in a bunch of parameters when writing the function and the variables would release memory once the function is complete, automatically. You can even write your functions in a separate file and use #Include to use them in your script.
I have recently started working on twisted not much familiar with its functions.I have a problem related to "deferToThread" method...my code is here to use this method
from twisted.internet.threads import deferToThread
from twisted.internet import reactor
results=[]
class Tool(object):
def exectool(self,tool):
# print "Test Class Exec tool running..........."
exec tool
return
def getResult(self,tool):
return results.append(deferToThread(self.exectool, tool))
to=Tool()
to.getResult(tools)
f=open(temp).read()
obj_tool=compile(f, 'a_filename', 'exec')
[ at 0x8ce7020, file "a_filename", line 1>, at 0x8cd4e30, file "a_filename", line 2>]
I am passing tools one by one in getResults() method it executs successfully & prints the results what script written in the file objects.
I have to store the result of tools executing in some variable so that I can save it in database.How to achieve this cause when i call re=to.getResult(tools) and print "re" it prints none.
I HAVE TO STORE ITS RESULTS IN DATABASE? IS THERE SOMETHING I CAN DO?
thanx in advance
There are two problems here.
First, deferToThread will not work if you never start the reactor. Hopefully this code snippet was actually extracted from a larger Twisted-using application where the reactor is running, so that won't be an actual problem for you. But you shouldn't expect this snippet to work unless you add a reactor.run() call to it.
Second, deferToThread returns a Deferred. The Deferred fires with the result of the callable you passed in. This is covered in the API documentation. Many APIs in Twisted return a Deferred, so you might want to read the documentation covering them. Once you understand how they work and how to use them, lots of things should be quite a bit easier.
I created a write func odbc list records files in sql table:
[R]
dsn=connector
write=INSERT INTO ast_records (filename,caller,callee,dtime) VALUES
('${ARG1}','${ARG2}','${ARG3}','${ARG4}')
prefix=M
and set it in dialplan :
exten => _0X.,n,Set(
M_R(${MIXMONITOR_FILENAME}\,${CUSER}\,${EXTEN}\,${DTIME})= )
when I excute it I get an error : ast_func_write: M_R Function not registered:
note that : asterisk with windows
First thing I saw was you were performing the call to the function incorrectly...you need to be assigning values, not arguments....try this:
func_odbc.conf:
[R]
dsn=connector
prefix=M
writesql=INSERT INTO ast_records (filename,caller,callee,dtime) VALUES('${VAL1}','${VAL2}','${VAL3}','${VAL4}');
dialplan:
exten => _0X.,1,Set(M_R()=${MIXMONITOR_FILENAME}\,${CUSER}\,${EXTEN}\,${DTIME})
If that doesn't help you, continue on in my list :)
Make sure func_odbc.so is being loaded by Asterisk. (from the asterisk CLI: module show like func_odbc)... If it's not loaded, it can't "build" your custom odbc query function.
Make sure your DSN is configured in /etc/odbc.ini
Make sure that /etc/asterisk/res_odbc.conf is properly configured
Make sure you're calling the DSN by the right name (I see it happen all the time)
enable verbose and debug in your Asterisk logging, do a logger reload, core set verbose 5, core set debug 5, and then try the call again. when the call finishes, review the log, you'll see much more output regarding what happened...
Regarding the answer from recluze...Not to call you out here, but using a PHP AGI is serious overkill here. The func_odbc function works just fine, why create more overhead and potential security issues by calling an external script (which has to use a interpreter program on TOP itself)?
you should call func odbc function as "ODBC_connector". connector should be use in the func_odbc.conf file [connector]. In the dialplan it should call like this.
exten=> _0x.,n,ODBC_connector(${arg1},${arg2})
I don't really understand the syntax you're trying to use but how about using AGI (with php) for this. Just define your logic in a php script and call it from your dialplan as:
exten => _0X.,n,AGI(script-filename.php,${CUSER},${EXTEN},${DTIME})